Housing with gradually varying thickness

ABSTRACT

A plastic housing comprises a top wall, a plurality of sidewalls extending from the top wall, each sidewall having a first end adjoining the top wall and an opposite second end, the sidewalls cooperatively defining an opening at the second ends thereof; the top wall has a uniform thickness, and a thickness of each of the sidewalls gradually decreases from the first end to the second end. Because of the shrinkage rate of the second ends of the sidewalls is much greater than the first ends of the sidewalls, the thickness of each sidewall is decreasing from the first end to the second end, therefore, the shrinkage deformation of the sidewalls can be even with the gradient thickness. The warping of the sidewalls is alleviated or is avoided.

BACKGROUND

1. Technical Field

The present disclosure relates to a housing, especially to a housing with a gradually varying thickness.

2. Description of Related Art

Many electronic devices or plastic products often include a plastic housing with an opening. For example, a rectangular plastic housing 10 of a Minus-Ion Air Purification Apparatus is shown in FIGS. 3 and 4 (related art). The housing 10 includes a top wall 104, four sidewalls 103 extending from the top wall 104 and the free ends 102 of the four sidewalls 103 forming an opening 101 opposite to the top wall 104. The thickness of the four sidewalls 103 and the top wall 104 is equal.

The housing 10 is formed via Plastic Injection Molding Processing. The sprue gate (not shown) of the mold (not shown) is defined beside the top wall 104, molten plastic is injected into the mold via the sprue gate and fill a rectangular cavity to form the housing 10. The molten plastic runs from where the top wall 104 is formed to where the sidewalls 103 are formed and is blocked at where the free ends 102 of the sidewalls 103 is formed, namely where the free end 102 of the each sidewall 103 is formed is a filling-end. Because of the long filling route to form the sidewalls 103, pressure reduced at where the free end 102 of the sidewalls 103 is formed is much greater than the another end near where the top wall 104 is formed. The more pressure reduced, the more shrinkage, so the shrinkage deformation of the free end 102 of the sidewall 103 is much greater than the end near the top wall 104. Uneven shrinkage deformation of the sidewalls 103 leads to warping of the housing 10. The warping of the housing 10 will affect the assembly.

Therefore, what is needed is a housing with a gradually varying thickness to overcome the above mentioned limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is a schematic view of a housing with a gradually varying thickness in accordance with an exemplary embodiment.

FIG. 2 is a cross-sectional view of the housing with a gradually varying thickness of FIG. 1, taken along line II-II.

FIG. 3 is a schematic view of a housing in prior art.

FIG. 4 is cross-sectional view of the housing of FIG. 3, taken along line IV-IV.

DETAILED DESCRIPTION

The disclosure including the accompanying drawings, is illustrated by way of example and not by way of limitation. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.

FIGS. 1 and 2 shows a plastic housing 100 of the disclosure. The plastic housing 100 is formed via Plastic Injection Molding Processing. The housing 100 includes a top wall 11 and a plurality of sidewalls 13 extending from the top wall 11, each sidewall 13 has a first end 14 adjoining to the top wall 11 and an opposite second end 15, the sidewalls 13 cooperatively define an opening 12 at the second ends 15 thereof. The distance between the top wall 11 and the opening 12 is greater than the thickness of the sidewalls 13, namely the height of the housing 100 is greater than the thickness of the sidewalls 13.

The top wall 11 has a uniform thickness, and a thickness of each sidewall 13 gradually decreases from the first end 14 to the second end 15. Each sidewall 13 has a maximum thickness at the first end 14 thereof.

In this embodiment, the top wall 11 of the housing is rectangular, and the number of the sidewalls 13 is four. The four sidewalls 13 have a same maximum thickness, minimum thickness and a same gradient rate of thickness from the first end 14 to the second end 15.

In other embodiment, the sidewall 13 of the housing 100 can also be cylindrical-shaped to form a cylinder housing 100. The housing 100 includes a round top wall 11 and a cylindrical sidewall 13 extending from the top wall 11, the sidewall 13 having a first end 14 adjoining the top wall 11 and an opposite second end 12, the sidewall 13 defining an opening 12 at the second end 15 thereof; the top wall 11 has a uniform thickness, and a thickness of the sidewall 13 gradually decreases from the first end 14 to the second end 15.

Because of the long filling route to form the sidewalls 13 in a plastic injection molding Process, pressure reduced at where the second end 15 of the sidewalls 13 is formed is much greater than the first end 14 of the sidewalls 13. The more pressure reduced, the more shrinkage rate, so the shrinkage rate of the second ends 15 of the sidewalls 13 is much greater than the first ends 14 of the sidewalls 13. The thickness of each sidewall 13 is decreasing from the first end 14 to the second end 15, therefore, the shrinkage deformation of the sidewalls 13 can be even with the gradient thickness. The warping of the sidewalls is alleviated or is avoided.

It is to be understood, however, that even though numerous characteristics and advantages of the present disclosure have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the present disclosure is illustrative only, and changes may be made in detail, especially in the matters of shape, size, and arrangement of parts within the principles of the present disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

What is claimed is:
 1. A plastic housing comprises: a top wall; and a plurality of sidewalls extending from the top wall, each sidewall having a first end adjoining the top wall and an opposite second end, the sidewalls cooperatively defining an opening at the second ends thereof; wherein the top wall has a uniform thickness, and a thickness of each sidewall gradually decreases from the first end to the second end.
 2. The housing according to claim 1, wherein each sidewall has a maximum thickness at the first end thereof.
 3. The housing according to claim 1, wherein the top wall is rectangular, and the number of the sidewalls is four.
 4. A plastic housing comprises: a round top wall; and a cylindrical sidewall extending from the top wall, the sidewall having a first end adjoining the top wall and an opposite second end, the side wall defining an opening at the second end thereof; wherein the top wall has a uniform thickness, and a thickness of the sidewall gradually decreases from the first end to the second end. 